If they are referring to the flexible connector pipes, those pipes are labeled for use only in accessible locations, not in a wall.

: We are replacing faucets. I found one (PF)with a single lever that will fit 4" center holes previously used for 2 levers. It has water supply lines already soldered to the housing but they are too short to reach our water supply. I was told at local home supply store to get some lines that will work as a patch line to the supply source. : Is this asking for trouble re future leaks ?? Is it risky ?